As you saw on the previous posts (put link to post2 and 3), all agricultural activities need air, water, soil and biodiversity, and therefore have an impact on the planet. This impact can be positive if agriculture respects the ecosystem or negative if natural resources are exploited excessively. Agriculture, climate change and food security are interconnected.1 Let’s see how!
The temperature increases
The Earth’s climate changes constantly due to small variations in the planet’s orbit. However, since the end of the 19th century the surface temperature has increased by 0.85 °C (0.65 to 1.06 °C) and the sea level has risen, as shown in the figures below (figure taken from the IPCC 2014 report):2
Human activity and the impact on climate change
This increase is driven in large part by human activities. Humans have altered the delicate balance of the planet by polluting air, water, soil and destroying biodiversity. The figure below (figure taken from the IPCC 2014 report)2 helps us to understand the human impact (anthropogenic) on the atmospheric concentration of greenhouse gases (GHG):
In fact, atmospheric concentrations of carbon dioxide (CO2) have increased by more than 1/3 since the beginning of the 19th century.2
As we mentioned in post 3: Carbon footprint of food = Greenhouse gases (GHG) expressed in Kg of CO2 that a product emits throughout its lifetime.
In fact, GHG capture the heat radiated by the sun and heat the earth.3 Just to mention, water vapor (H2O) is an abundant GHG as well.3 However, due to its impact on the climate (through the formation of clouds and precipitation), and its low human impact, we are not going into details about this one.
The following figure shows the sources and concentration of GHG in the atmosphere.
Believe me, this is really interesting:
warming is happening due to an increased emission of GHG, especially caused by
human activity (fossil fuels, industrial processes, increased use of natural
resources, intensive agriculture, livestock farming and deforestation).
FAO (Food and Agriculture Organization of the United Nations) estimates that between the years of 2003 and 2013, natural disasters triggered by natural hazards caused economic losses valued in 1.5 trillion US dollars. In developing countries, during the same time period, these disasters cost about 550 billion US dollars, affecting 2 billion people. About 22% of these damages belong to agriculture and its subsectors (crops, livestock, fisheries and forestry).4
The climate change and the agriculture
Climate change not only causes economic losses, but also has direct and indirect effects on agricultural productivity, such as variations in rainfall regimes, droughts, floods, geographic redistribution of biodiversity (including pests)5 and diseases.1 The large amounts of CO2 absorbed by the oceans also cause acidification which results in deteriorating marine ecosystems.6
One of the biggest consequences of climate change are the natural disasters that are responsible for agricultural losses which have alarming effects on food security.1
So what happens to the earth?
Our planet, the Earth, is overweight (403 ppm CO2 eq. (average value of year 2016)) and increasing.7 Depending on the actions we take, scientists predict that the temperature will rise up to 4 °C by the year 2100 (450 ppm CO2 eq. will increase the planet’s temperature 2 °C and 1000 ppm CO2 eq. 4 °C).2 This means not only an increase in the number of natural disasters but, as the planet gets hotter, it will be very difficult to produce food in the tropics, which will cause biodiversity to migrate (including people) to more peripheral regions in the planet, and as a consequence will result in a tremendous impact on human well-being.5
It is evident that the impact of climate change on food and agriculture is interconnected with environmental, social and economic fields (i.e. food security, nutrition, health, and human migration).1
This is a very serious problem! So, what can we do, and how does it relate to food? To answer these questions, let’s have a close look at the human contribution (our contribution) to the GHG emissions.
Human sources of GHG
The following figure shows the anthropogenic sources of GHG:
We can see that “Energy Production” is by far the biggest source of GHG, but let’s have a look at the second one, “Agricultural Processes” which accounts for 21% of the GHG emitted.1
GHG coming from Agriculture
The following figure shows the share of agricultural emissions in CO2 eq. in year 2014 by source and at a global level:1
The main cause of agricultural GHG emissions is by far enteric fermentation (the digestion processes of ruminants such as cattle, sheep, goats, buffalo, deer, giraffes and camels).
Enteric fermentation is the main source in Latin America and the Caribbean with 58% (followed by manure left on pasture with 23% and synthetic fertilizers with 6%), in Southern Asia with 46%, in Sub-Saharan Africa with 40%, in Northern Africa and Western Asia with 39% and in developed countries with 37%. Only in Oceania (excluding Australia and New Zealand) and in Eastern and Southeastern Asia is the main source of agricultural GHG derived from the cultivation of organic soils with 59% (followed by enteric fermentation with 14% and manure management with 14%) and rice cultivation with 26% (followed by enteric fermentation with 24% and synthetic fertilizer with 17%), respectively.1
But let’s not mistake the problem. Because cows alone are not. They actually contribute to soil fertility inside an healthy ecosystem. The problem is the number cows being raised to meet human demand.
A recent scientific study has quantified the mass of life on earth (biomass) and has shown that within the animal kingdom (2% of the entire biomass), there are more than 10x more humans than wild animals and that there are about 40% more livestock than humans.8 This is crazy!
To keep producing meat and to satisfy the world’s food and energy demand of the growing population, the most important forests and savannas will need to be destroyed!1 And if deforestation takes place, what will happen? What is already happening?
Deforestation, Climate Change and the Carbon Cycle
To understand the important role of forests in the weather, we need to talk about the carbon cycle. But let’s start by linking some concepts. Remember CO2 and CH4, our very important GHG, both contain one atom of carbon (C).
However, C is not only found in the atmosphere. Actually, there are five global C pools (as shown in the following figure too):9
- the oceanic pool;
- the geological pool (which includes the fossil fuels);
- the soil pool (comprising the soil organic C and the soil inorganic C);
- the atmospheric pool and;
- the biotic pool (comprising live biomass and detritus material)
There is a strong interaction between the terrestrial and atmospheric C pools through photosynthesis, respiration and soil metabolism. The potential of a healthy soil becomes evident in sequestering atmospheric CO2 in both the biotic and pedologic C pools (620 and 2500 Pg, respectively). Additionally, deforestation impoverishes the soil releasing ca. 1.6 Pg C/Year.9
So, YES, forests are very important, not only because they produce oxygen, but especially because of their capacity to keep a healthy soil which allows the capture of atmospheric CO2.
The ecofriendly agriculture
But we need food, right? Luckily, we can also have a healthy soil through ecofriendly agriculture. Many scientists, farmers and international organizations believe that the understanding of the soil’s role in climate stability and agricultural productivity will trigger the abandonment of conventional practices (i.e. tillage, crop residue removal, mono-cropping, excessive grazing and excessive use of chemical fertilizers and pesticides) and adoption of organic agriculture.
The Potential of Carbon Sequestration through Organic Agriculture
According to FAO: “Organic Agriculture is a holistic production management system which promotes and enhances agro-ecosystem health, including biodiversity, biological cycles, and soil biological activity.”10
Also referred as Agroecology, it is based on applying ecological concepts and principles to optimize interactions between plants, animals, humans and the environment while taking into consideration the social aspects that need to be addressed for a sustainable and fair food system.11
This sustainable form of agriculture takes care of the whole ecosystem! Isn’t it great?
Some sustainable agricultural practices (management practices) that contribute to CO2 sequestration are:9
- reduction/elimination of mechanical tillage;
- application of cover crops into the rotation cycle;
- increasing soil fertility through biological means (i.e. compost, animal manures and nitrogen fixation plants that also contribute to mitigate N2O);
- adoption of conservation-effective measures to minimize soil and water losses (e.g. soil water storage, drip irrigation);
- a better use of the complex farming systems including complex rotations, mixed farming (i.e. crop-livestock) and agroforestry techniques that efficiently use resources, enhance biodiversity and mimic natural ecosystems.
So much information… What can we do now??
Climate change is a big problem which concerns all of us. Choose walking, riding a bike or public transportation instead of driving; heat and cool only the necessary; reevaluate, reconceptualize, restructure, redistribute, relocate, reduce, reuse and recycle.
Regarding food, let’s start by making connections. Food is directly linked with the farmers, the land, the watersheds and the climate. And our health is a reflection of the quality and quantity of the food we consume. At the end, it is all interconnected!
If we reduce waste, change our diet to eat less meat and dairy, support agroecology, local markets and sustainable intensification to increase yields on underperforming crops, and protect the forest, we may be able stop global warming and feed more than nine billion people a healthy diet.
Let’s save the forest, promote and support Organic Agriculture and local markets!
Some great initiatives out there are making a huge difference to help spread good agricultural practices. Organizations like A Growing Culture are promoting and facilitating collective learning between farmers, empowering smaller farmers, supporting agroecological innovations and a sustainable food system.
Another great one is the Godan that shares agricultural and nutritional data globally encouraging collaboration and cooperation that will bring together stakeholders to solve long-standing global problems.
The Equator Initiative on the other hand, recognizes outstanding local sustainable development solutions supporting the formation of resilient communities. The projects being awarded are doing amazing things, it is really worth getting to know them!
An interesting website with more information about food and climate change is the Food Climate Research Network who is raising awareness and connecting stakeholders with the common interest of understanding and building sustainable food systems.
In Drawdown and ZERI, you can find sustainable practices that are already being implemented and; the Ellen Macarthur Report circular solutions that can change the food system within cities. Worth knowing them!
Importantly, children are also actively involved. Fridays for future, the movement started by Greta Thunberg, a Swedish high school student who in August 2018, started school strikes on Fridays asking her government (and later the world), to take political actions to reduce emissions caused by climate change in accordance with the Paris Agreement. The movement has expand and is now present in 101 countries around the world.
Juliana versus USA, is a lawsuit filed in 2015 by 21 young plaintiffs asserting that the federal government violated their constitutional rights to life, liberty and prosperity (only possible inside a clean environment) by causing dangerous carbon dioxide concentrations. Let’s stay tuned and see how this demand develops.
Another very interesting case is the lawsuit known as “The Huaraz Case”. In 2015, Saúl Luciano Lliuya, a mountain guide living in Huaraz, Peru, filed a lawsuit against the German energy company RWE to be responsible for its carbon emissions. The global increase in carbon in the atmosphere is causing the melting of the Peruvian glacial risking to destroy the home of his community. He asks for the construction of a dam to protect his home for the future effects of climate change.
A proposal worth mentioning is the Yasuní-ITT Initiative in which the government of Ecuador proposed to the world in 2010, to maintain the oil reserves that are located below one of the regions with the greatest biodiversity in the world, Yasuni National Park in the Ecuadorian Amazon, in exchange for the potential oil revenues (3.6 billion US dollars). The objective of the initiative was to conserve biodiversity, protect indigenous peoples living in voluntary isolation and avoid CO2 emissions. Unfortunately, fundraising was insufficient and oil has been extracted since 2016.
Ecuador has also been a pioneer in the protection of nature at the political level, being the first country in the world where “Nature is a subject of law”, meaning that the Ecuadorian Constitution (or Montecristi Constitution) recognizes since 2008 the right to life of species beyond utility or affectation for humans. It protects life reproduction, both in the ecological and evolutionary sense claiming the right to integral restoration. It also recognizes that the rights of people and nature complement and enhance each other, and that in nature there are no geographical barriers. The constitutions, however, does not oblige to have an untouched nature or animal welfare, allowing large-scale mining even in fragile areas among other economic activities that destroy nature. Undoubtedly, a lot of work still needs to be done…
Recently, an important philosophical claim to respect nature has also come from the Vatican with the encyclical Laudato si’ written by Pope Francis. The document emphasizes the fact that the human being is not the owner of nature, but only a part of it, which depends on it to exist and exalts the human duty to preserve it. It is worth reading!
Supporting existing and outstanding initiatives that are working to solve the problem is of course important. However, each one of us can be part of the solution by properly choosing our food, what and where we are buying, from whom we are buying and at what price. These little gestures can really start changing the world!
By M. S. Gachet et N. Zanuto
1 FAO, 2016: The State of Food and Agriculture. Climate change, Agriculture and Food Security.
2 IPCC, 2014. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.
3 NASA. The Causes of Climate Change.
4 FAO, 2015: The impact of disasters on agriculture and food security.
5 Pecl, G.T, et al. Biodiversity redistribution under climate change: Impacts on ecosystems and human well-being. Science (2017) 355(6332).
6 FAO, 2010: Environmental consequences of oceans acidification: a threat to food security.
7 Dlugokencky, E. Annual Mean Carbon Dioxide Data. Earth System Research Laboratory. National Oceanic & Atmospheric Administration.
8 Nar-On, Y.M., et al. The biomass distribution on Earth.
9 Solaw-FAO. Report 4B – Soil carbon sequestration. Lal R.
10 FAO. Organic Agriculture.
11 FAO. Agroecology Knowledge Hub.